So Closely Related and Yet So Different: Strong Contrasts Between the Evolutionary Histories of Species of the Cardamine pratensis Polyploid Complex in Central Europe
Year: 2020
Type: article
Abstract: Recurrent polyploid formation and weak reproductive barriers between independent polyploid lineages generate intricate species complexes with high diversity and reticulate evolutionary history. Uncovering the evolutionary processes that formed their present-day cytotypic and genetic structure is a challenging task. We studied the species complex ofCardamine pratensis, composed of diploid endemics in the European Mediterranean and diploid-polyploid lineages more widely distributed across Europe, focusing on the poorly understood variation in Central Europe. To elucidate the evolution of Central European populations we analyzed ploidy level and genome size variation, genetic patterns inferred from microsatellite markers and target enrichment of low-copy nuclear genes (Hyb-Seq), and environmental niche differentiation. We observed almost continuous variation in chromosome numbers and genome size inC. pratensiss.str., which is caused by the co-occurrence of euploid and dysploid cytotypes, along with aneuploids, and is likely accompanied by inter-cytotype mating. We inferred that the polyploid cytotypes ofC. pratensiss.str. are both of single and multiple, spatially and temporally recurrent origins. The tetraploidCardamine majovskyievolved at least twice in different regions by autopolyploidy from diploidCardamine matthioli. The extensive genome size and genetic variation ofCardamine rivularisreflects differentiation induced by the geographic isolation of disjunct populations, establishment of triploids of different origins, and hybridization with sympatricC.matthioli. Geographically structured genetic lineages identified in the species under study, which are also ecologically divergent, are interpreted as descendants from different source populations in multiple glacial refugia. The postglacial range expansion was accompanied by substantial genetic admixture between the lineages ofC.pratensiss.str., which is reflected by diffuse borders in their contact zones. In conclusion, we identified an interplay of diverse processes that have driven the evolution of the species studied, including allopatric and ecological divergence, hybridization, multiple polyploid origins, and genetic reshuffling caused by Pleistocene climate-induced range dynamics.
Source: Frontiers in Plant Science
Institutions: Slovak Academy of Sciences, Institute of Botany of the Slovak Academy of Sciences, Charles University, Central European Institute of Technology, Masaryk University, Central European Institute of Technology – Masaryk University, University of South Bohemia in České Budějovice, Technická univerzita vo Zvolene, University of Pavol Jozef Šafárik
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,684
Awards: Pathways and consequences of polyploidy and chromosomal variation in plant evolution - three cases from the model family Brassicaceae, G2878992496, G3496015395, Pôvod polyploidných komplexov: úloha polyploidizácie a geografickej a ekologickej izolácie, Ribosomal RNA genes - travellers in time and the genomes, G6231564467, How hybridisation and allopolyploidisation affect the diversity in three Brassicaceae tribes, G7475903712, G8136781011, G9000262362
OpenAlex ID: W3113310127